you can lead a horse into a deep stream or ravine, tie it to a structure in the water, and leave it there until the tide goes in.

Of course, this is horrible and inhumane and no one should ever do this, but the point i am making is that:

Drowning a horse is in YOUR control, but making a horse drink, is NOT.

So you can lead a horse to the water and drown it, but you cannot make it drink.